Image capturing device with touch screen for adjusting camera settings

ABSTRACT

Several methods for operating a built-in digital camera of a portable, handheld electronic device are described. In one embodiment, the device receives a user selection (e.g., tap, tap and hold, gesture) of a region displayed on the display screen (e.g., touch sensitive screen). A touch to focus mode may then be initiated in response to the user selection and exposure and focus parameters determined and adjusted. Then, an automatic scene detection mechanism can determine whether a scene has changed. If the scene has changed, then the touch to focus mode ends and a default automatic focus mode initiates. This mode sets a new exposure metering area and focus area prior to determining and adjusting exposure and focus parameters, respectively.

The present application is related to the commonly-owned,previously-filed provisional application: application Ser. No.61/083,455, filed Jul. 24, 2008, entitled “CAMERA INTERFACE IN APORTABLE HANDHELD ELECTRONIC DEVICE,” which is incorporated by referencein its entirety herein.

An embodiment of the invention is generally related to image capturingelectronic devices, having a touch sensitive screen for controllingcamera functions and settings.

BACKGROUND

Image capturing devices include cameras, portable handheld electronicdevices, and electronic devices. These image capturing devices can usean automatic focus mechanism to automatically adjust focus settings.Automatic focus (hereinafter also referred to as “autofocus” or “AF”) isa feature of some optical systems that allows them to obtain and in somesystems to also continuously maintain correct focus on a subject,instead of requiring the operator to adjust focus manually. Automaticfocus often uses a computer to run a miniature motor that focuses thelens for you. Focusing is the moving of the lens in and out until thesharpest possible image of the subject is projected onto the film orother image sensor. Depending on the distance of the subject from thecamera, the lens has to be a certain distance from the film to form aclear image.

A conventional camera automatically focuses on the center of a display(e.g., viewfinder) or automatically selects a region of the display tofocus (e.g., identifying faces using face detection algorithms).Alternatively, the camera overlays several focal boxes on a previewdisplay through which a user can cycle and select, for example, with ahalf-press of button (e.g., nine overlaid boxes in SLR cameras). Tofocus on a target subject, a user also may center a focal region on arandom subject, hold the focus, and subsequently move the camera so thatthe focal region is centered at the target subject.

SUMMARY

Several methods for operating a built-in digital camera of a portable,handheld electronic device are described. In one embodiment, the devicereceives a user selection (e.g., tap, tap and hold, gesture) of a regiondisplayed on the display screen (e.g., touch sensitive display screen).A touch to focus mode may then be initiated and an exposure meteringarea can then automatically be determined based on the user selectionand displayed on the screen. Then a focus area can be automaticallydetermined based on the user selection and an automatic focus scaninitiated for the focus area. Next, the automatic exposure mechanismadjusts exposure parameters based on the metering area.

In another embodiment, the display screen is a touch sensitive screenand the user selection is one of a tap, a tap and hold, a single fingergesture, and a multi-finger gesture.

In another embodiment, an automatic detect scene change mechanism isexecuted. This mechanism can automatically monitor a luminancedistribution of the selected region for each image captured by thedevice during the touch to focus mode. The mechanism automaticallycompares a first luminance distribution of the selected region for afirst image and a second luminance distribution of the selected regionfor a second image. Then, the mechanism automatically determines whethera scene has changed by comparing first and second luminancedistributions of the selected region for the respective first and secondimages. If a scene has changed, then the mode changes to a continuousautomatic focus mode in which the exposure metering area is based on thefull screen and the focus area automatically moves from the selectedregion to a center of the screen.

These operations can be initiated after the device enters an imagecapturing mode or other mode. For example, the device may have manyfunctions and capabilities (e.g., the device may be a smart phone orpersonal digital assistant (PDA) which can send and receive emails,allow surfing of the internet, create documents, and also act as acamera), and a user can place the device into camera mode in order tocause it to begin these operations. In an embodiment, the device is notperforming these operations when it is not in camera mode.

Other embodiments are also described. The above summary does not includean exhaustive list of all aspects of the present invention. It iscontemplated that the invention includes all systems and methods thatcan be practiced from all suitable combinations of the various aspectssummarized above, as well as those disclosed in the Detailed Descriptionbelow and particularly pointed out in the claims filed with theapplication. Such combinations may have particular advantages notspecifically recited in the above summary.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments of the invention are illustrated by way of example andnot by way of limitation in the figures of the accompanying drawings inwhich like references indicate similar regions. It should be noted thatreferences to “an” or “one” embodiment of the invention in thisdisclosure are not necessarily to the same embodiment, and they mean atleast one.

FIG. 1 shows a portable handheld device having a built-in digital cameraand a touch sensitive screen, in the hands of its user undergoing a tapselection during an image capture process, in accordance with oneembodiment.

FIG. 2 is a flow diagram of operations in the electronic device duringan image capture process, in accordance with one embodiment.

FIG. 3 is a flow diagram of operations in the electronic device duringan image capture process, in accordance with some embodiments.

FIG. 4 illustrates a display screen of an image capturing device, inaccordance with one embodiment.

FIG. 5 illustrates a display screen of an image capturing device inaccordance with an embodiment.

FIG. 6 shows the portable handheld electronic device undergoing amulti-finger gesture during an image capture process, in accordance withan embodiment.

FIG. 7 shows a block diagram of an example, portable handheldmultifunction device in which an embodiment of the invention may beimplemented.

FIG. 8 shows an example of a data processing system, in accordance withan embodiment of the present invention.

DETAILED DESCRIPTION

Several methods for operating a built-in digital camera of a portable,handheld electronic device are described. In one embodiment, the devicereceives a user selection (e.g., tap, tap and hold, gesture) of a regiondisplayed on the display screen (e.g., touch sensitive display screen).A touch to focus mode may then be initiated and an exposure meteringarea can then automatically be determined based on the user selectionand displayed on the screen. Then a focus area can be automaticallydetermined based on the user selection and an automatic focus scaninitiated for the focus area. Next, the automatic exposure mechanismadjusts exposure parameters based on the metering area.

An automatic detect mechanism may also be implemented to determine whena scene changes. In one embodiment, this mechanism can automaticallymonitor a luminance distribution of the selected region for imagescaptured by the device during the touch to focus mode. The mechanismautomatically compares a first luminance distribution of the selectedregion for a first image and a second luminance distribution of theselected region for a second image. Then, the mechanism automaticallydetermines whether a scene has changed by comparing first and secondluminance distributions of the selected region for the respective firstand second images. If a scene has changed, then the mode changes to adefault automatic focus mode in which the exposure metering area isbased on the full screen and the focus area automatically moves from theselected region to a center of the screen.

A user can easily select a region for automatic exposure and focusadjustments during a touch to focus mode. An automatic scene changemechanism determines whether a scene has changed and alters the exposureand focus areas if necessary.

In this section several embodiments of this invention are explained withreference to the appended drawings. The shapes, relative positions andother aspects of the parts described in the embodiments are not limitedonly to those shown, which are meant merely for the purpose ofillustration.

FIG. 1 shows an image capturing device 100, which can be a portablehandheld electronic device, having a built-in digital camera and a touchsensitive screen 104 in the hand of its user, undergoing a userselection (e.g., tap, tap and hold, gesture) during an image captureprocess. The device 100 may be an IPHONE device by Apple Inc., ofCupertino, Calif. Alternatively, it could be any other portable handheldelectronic device that has a built-in digital camera and a touchsensitive screen. The built-in digital camera includes a lens 103located in this example on the back face of the device 100. The lens maybe a fixed optical lens system or it may have focus and optical zoomcapability. Although not depicted in FIG. 1, inside the device 100 arean electronic image sensor and associated hardware circuitry and runningsoftware that can capture digital images or video of a scene 102 that isbefore the lens 103.

The digital camera functionality of the device 100 includes anelectronic or digital viewfinder. The viewfinder displays live, capturedvideo (e.g., series of images) or still images of the scene 102 that isbefore the camera, on a portion of the touch sensitive screen 104 asshown. In this case, the digital camera also includes a soft or virtualshutter button whose icon 105 is displayed by the screen 104, directlybelow the viewfinder image area. As an alternative or in addition, aphysical shutter button may be implemented in the device 100. In oneembodiment, the device 100 may be placed in either the digital cameramode or the mobile telephone mode, in response to, for example, the useractuating a physical menu button 108 and then selecting an appropriateicon on the touch sensitive screen 104. The device 100 includes all ofthe needed circuitry and/or software for implementing the digital camerafunctions of the electronic viewfinder, shutter release, and automaticimage capture parameter adjustment (e.g., automatic exposure, automaticfocus, automatic detection of a scene change) as described below.

In FIG. 1, the user can perform a selection on the touch sensitivescreen 104 as shown by, for example, tapping the screen with a stylus orfinger. The user positions the tap selection on a preview portion of thetouch screen. The device 100 has detected this tap and has automaticallydrawn a metering area 96 (in this case, the closed contour that has abox shape), centered around the location of the touch down, the subject99. The user may lift off his finger, which in turn can signal thecamera to accept the final location of the user selection and theunderlying portion of the image as the selected region of the scene.Once the user has finalized the selection of this selected region, hecan command the digital camera to take a picture or record video, afterthe image capture parameters are automatically adjusted based on theselected region. A flow diagram of operations for automaticallyadjusting these parameters, in accordance with the above, is shown inFIG. 2.

FIG. 2 is a flow diagram of operations in the electronic device duringan image capture process, in accordance with one embodiment. Afterhaving powering on the device 100 and placing it in digital camera modeat block 202, a view finder function begins execution which displaysstill images or video (e.g., a series of images) of the scene 102 thatis before the camera lens 103 at block 203. The user aims the cameralens so that the desired portion of the scene appears on the previewportion of the screen 104. A default autofocus mode is initiated oncethe camera is placed in the digital camera mode. The default autofocusmode can determine focus parameters for captured images or video of thescene at block 204. The default automatic focus mode can set an exposuremetering area to substantially full-frame and corresponding full-screenat block 205. The default automatic focus mode can set the focus area toa center of frame and corresponding center of the screen at block 206.The continuous automatic focus mode is used to detect when a subject isout of focus and then estimate new focus parameters to refocus the lenswith respect to the subject.

While monitoring the screen, a camera application (or a touch screenapplication) running in the device 100 receives a user selection (e.g.,tap, tap and hold, gesture) of a region displayed on the display screen(e.g., touch sensitive display screen) and then stores screencoordinates of its location at block 207. A touch to focus mode may thenbe automatically initiated in response to the user selection at block208 and an exposure metering area can then automatically be determinedbased on the user selection and displayed on the screen at block 210.The exposure metering area may be displayed as a contour surrounding theregion selected by the user and have predetermined dimensions based on alocation of the user selection with respect to the screen.

In an embodiment, the selected region is moved around the previewportion of the touch screen, in lock step with the user moving herfinger gesture along the surface of the touch screen. This selectedregion may be finalized, for example, in response to the user liftingoff his finger. The selected region of the image may be a predictedregion of pixels that are about coextensive with the location of theuser selection. Alternatively, the selected region may be an object inthe scene located at or near the location of the user selection, asdetected by the camera application using digital image processingtechniques. Alternatively, the user can adjust the dimensions of theselected region, for example, by moving anchors defining the dimensionsof the selected region, which can also be touch-based.

Once the metering area has been determined, an automatic exposuremechanism, which may be executed by a processing circuit or processinglogic, is initiated and allowed to stabilize at block 212. Next, anautomatic focus scan, which may be executed by the processing circuit orprocessing logic, is initiated based on the location of the selectedregion at block 214. In one embodiment, a focus area is associated withthe selected region and is set at approximately the same location andsize as the selected region. The device automatically focuses on aportion of a scene using a focus area associated with the selectedregion.

Next, the automatic exposure mechanism can determine exposure parametersusing the metering area at block 216. Exposure parameters (e.g.,exposure time, integration time of image sensor) can be adjusted basedupon characteristics (e.g., brightness) of the metering area. Theexposure mechanism may use flat metering using all pixels of themetering area or center weighted metering.

In an alternative embodiment, separate user selections can determine theexposure metering area and the focus area. For example, a first userselection (e.g., tap and hold) determines the metering area and a seconduser selection (e.g., tap) determines the focus area.

In some embodiments, the processing logic can automatically determinewhether a portion of the scene associated with the focus area haschanged by monitoring a luminance distribution of the focus area atblock 218. If a scene has not changed, then the method returns to block216 for continuous adjustment of automatic exposure if necessary. If thescene has changed at block 218, then the touch to focus mode stops atblock 220 and the method returns to the default autofocus mode todetermine focus parameters for captured images or video of the new sceneat block 204. More details regarding detection of a changed scene arediscussed in FIG. 3.

In one embodiment, the default autofocus mode is a continuous automaticfocus mode that can set the exposure metering area to substantiallyfull-frame and corresponding full-screen. The continuous automatic focusmode can move the focus area from the selected region to a center offrame and corresponding center of the screen. Alternatively, data fromthe histograms or an image contrast source may be evaluated to determinea new location and size of the focus area.

The continuous automatic focus mode is used to detect when a subject isout of focus and then estimate new focus parameters to refocus the lenswith respect to the subject. The continuous automatic focus mode canperform an automatic focus scan for a lens of the image capturing deviceand obtains focus scores associated with the automatic focus scan. In anembodiment, a focus score is a scene-dependent measure of contrast.Next, the autofocus mechanism can determine whether a current focusscore is within an acceptable band of focus scores. A refocus scan isneeded if the current focus score is outside of the acceptable band offocus scores.

FIG. 3 is a flow diagram of operations in the electronic device duringan image capture process to determine whether a scene has changed, inaccordance with certain embodiments. As discussed above at block 203 ofFIG. 2, processing logic can display on the display screen images orvideo captured by the image capturing device. The processing logic canreceive a user selection of a region (e.g., selected region) displayedon the display screen, which initiates a touch to focus mode, asdiscussed in block 207 and 208 of FIG. 2. In an embodiment, the displayscreen is a touch sensitive screen and the user selection is one of atap, a tap and hold, a single finger gesture, and a multi-fingergesture. An exposure metering area and focus area may be based upon anapproximate size and location of the selected region. These metering andfocus areas are used for adjusting exposure and focus parameters,respectively.

After the operations of blocks 202-216 are completed as discussed above,at block 306 of FIG. 3, the processing logic, executing an automaticdetect mechanism, can automatically monitor a luminance distribution ofthe selected region associated with a focus area for each image capturedby the device. At block 308, the processing logic automatically comparesa first luminance distribution of the selected region for a first imageand a second luminance distribution of the selected region for a secondimage. At block 310, the processing logic automatically determineswhether the first and second luminance distributions of the selectedregion for the respective first and second images are different by apredetermined value. The automatic detect mechanism may be continuouslyperformed to determine whether a scene or a portion of scene associatedwith the focus area has changed by comparing luminance distributions forthe focus area of different images.

In one embodiment, a vector having numerous elements (e.g., 16) can berepresented as histogram. A histogram of luminance distribution for thefirst image can be compared with a histogram of luminance distributionfor the second image. If values of the first and second luminancedistributions are approximately equal to each other or within apredetermined value of each other, then the touch to focus mode adjustsexposure parameters for the exposure metering area associated with theselected region as discussed at block 216 of FIG. 2. If the scene orportion of the scene associated with the focus area has changed, thenthe touch to focus mode stops and a default automatic focus mode isinitiated to determine focus parameters for captured images of the newscene as discussed at block 220 of FIG. 2.

FIG. 4 illustrates a display screen of an image capturing device inaccordance with one embodiment. A selected region 410 is selected by auser touching a touch sensitive screen 400 in some manner (e.g., tap,tap and hold, single touch gesture, multi-touch gesture) with a userinput (e.g., finger, thumb, stylus, etc.). The selected region mayrepresent approximately a location and a size of the user selection. Theuser selection triggers a touch to focus mode, which initiates anautomatic exposure mechanism. This mechanism determines a size andlocation of an exposure metering area 420 based on the size and/orlocation of the selected region. For example, the metering area may forma contour surrounding the selected region. In an embodiment, theexposure metering area 420 is displayed to the user while the selectedregion 410 is not displayed to the user. A focus area may be similar tothe size and location of the selected region. Automatic exposure andfocus mechanisms adjust exposure and focus parameters, respectively, asdescribed in the flow charts of FIGS. 2 and 3. An automatic detectmechanism then determines whether a scene changes. If a scene changes,then the touch to focus mode terminates and a default automatic focusmode starts (e.g., continuous automatic focus mode). The exposure andfocus areas are then automatically adjusted as illustrated in FIG. 5.

FIG. 5 illustrates a display screen of an image capturing device inaccordance with an embodiment. A focus area (not shown) is centered withrespect to a center 510 of the display screen 500. The default automaticfocus mechanism determines a size and location of an exposure meteringarea 520 in response to a scene change determination. The exposuremetering area can be approximately equal to a full screen size asillustrated in FIG. 5. The focus area may be similar in size compared tothe metering area 520 or a different size.

FIG. 6 shows the portable handheld electronic device undergoing amulti-finger gesture during an image capture process, in accordance withan embodiment. In particular, the thumb and index finger are broughtclose to each other or touch each other, simultaneously with their tipsbeing in contact with the surface of the screen 104 to create twocontact points thereon. The user positions this multi-touch gesture,namely the two contact points, at a location of the image of the scene102 that corresponds to an object in the scene (or portion of the scene)to which priority should be given when the digital camera adjusts theimage capture parameters in preparation for taking a picture of thescene. In this example, the user has selected the location where aperson appears between a mountainside in the background and a tree inthe foreground.

In response to detecting the multi-touch finger gesture, the device 100may cause a contour 106, in this example, the outline of a box, to bedisplayed on the screen 104, around the location of the detectedmulti-finger gesture. The contour 106 is associated, e.g. by softwarerunning in the device 100, with an exposure metering area for settingexposure parameters. The user can then contract or expand the size ofthe metering area, by making a pinching movement or a spreadingmovement, respectively, with her thumb and index fingers of her handwhile the fingertips remain in contact with the touch sensitive screen104. The device 100 has the needed hardware and software to distinguishbetween a pinching movement and a spreading movement, and appropriatelycontracts or expands the size of the metering area. Gesture movementsmay include single or multi-point gestures (e.g., circle, diagonal line,rectangle, reverse pinch, polygon).

Turning now to FIG. 7, a block diagram of an example image capturingdevice 700 is shown, in accordance with an embodiment of the invention.The device 700 may be a personal computer, such as a laptop, tablet, orhandheld computer. Alternatively, the device 700 may be a cellular phonehandset, personal digital assistant (PDA), or a multi-function consumerelectronic device, such as the IPHONE device.

The device 700 has a processor 704 that executes instructions to carryout operations associated with the device 700. The instructions may beretrieved from memory 720 and, when executed, control the reception andmanipulation of input and output data between various components ofdevice 700. Memory 720 may be or include a machine-readable medium.

Although not shown, the memory 720 may store an operating system programthat is executed by the processor 704, and one or more applicationprograms are said to run on top of the operating system to performdifferent functions described below. The touch sensitive screen 704displays a graphical user interface (GUI) to allow a user of the device700 to interact with various application programs running in the device700. The GUI displays icons or graphical images that representapplication programs, files, and their associated commands on the screen704. These may include windows, fields, dialog boxes, menus, buttons,cursors, scrollbars, etc. During operation, the user can select andactivate various graphical images to initiate functions associatedtherewith.

The touch screen 704 also acts as an input device, to transfer data fromthe outside world into the device 700. This input is received via, forexample, the user's finger(s) touching the surface of the screen 704.The screen 704 and its associated circuitry recognize touches, as wellas the position and perhaps the magnitude of touches and their durationon the surface of the screen 704. These may be done by a gesturedetector program 722 that may be executed by the processor 704. Notethat a dedicated processor may be provided to process touch inputs, inorder to reduce demand for a main processor of the system. The touchsensing capability of the screen 704 may be based on technology such ascapacitive sensing, resistive sensing, or other suitable solid statetechnologies. The touch sensing may be based on single point sensing ormulti-point or multi-touch sensing. Single point touch sensing iscapable of only distinguishing a single touch, while multi-point sensingis capable of distinguishing multiple touches that occur at the sametime.

Still referring to FIG. 7, camera functionality of the device 700 may beenabled by the following components. An image sensor 706 (e.g., CCD,CMOS based device, etc.) is built into the device 700 and may be locatedat a focal plane of an optical system that includes the lens 703. Anoptical image of a scene before the camera is formed on the image sensor706, and the sensor 706 responds by capturing the scene in the form of adigital image or picture or video consisting of pixels that will then bestored in memory 720. The image sensor 706 may include an image sensorchip with several options available for controlling how an image iscaptured. These options are set by image capture parameters that can beadjusted automatically, by the camera application 728. The application728 can make automatic adjustments (e.g., automatic exposure mechanism,automatic focus mechanism, automatic scene change detection, continuousautomatic focus mechanism), that is without specific user input, tofocus, exposure and other parameters based on a selected portion of thescene that is to be imaged.

In some embodiments, the image capturing device 700 includes a built-indigital camera and a touch sensitive screen. The digital camera includesa lens to form optical images stored in memory. The touch sensitivescreen, which is coupled to the camera, displays the images or video.The device further includes a processing system (e.g., processor 704),which is coupled to the screen. The processing system may be configuredto receive a user selection (e.g., a tap, a tap and hold, a singlefinger gesture, and a multi-finger gesture) of a region displayed on thetouch sensitive screen. The processing system may be further configuredto initiate a touch to focus mode based on the user selection. The touchto focus mode automatically focuses using a focus area associated withthe selected region. The processing system may be configured toautomatically monitor a luminance distribution of the focus area forimages captured by the device to determine whether a portion of a sceneassociated with the selected region has changed.

The processing system may be configured to automatically determine alocation of the focus area based on a location of the selected region.The processing system may be configured to terminate the touch to focusmode if the scene changes and to initiate a default automatic focusmode. For the default automatic focus mode, the processing system canset an exposure metering area to substantially full screen, rather thanbeing based on the selected region. For the default automatic focusmode, the processing system can move a location of the focus area fromthe selected region to a center of the screen.

Still referring to FIG. 7, the device 700 may operate not just in adigital camera mode, but also in a mobile telephone mode. This isenabled by the following components of the device 700. An integratedantenna 709 that is driven and sensed by RF circuitry 711 is used totransmit and receive cellular network communication signals from anearby base station (not shown). A mobile phone application 724 executedby the processor 704 presents mobile telephony options on the touchsensitive screen 104 for the user, such as a virtual telephone keypadwith call and end buttons. The mobile phone application 724 alsocontrols at a high level the two-way conversation in a typical mobiletelephone call, by allowing the user to speak into the built-inmicrophone 714 while at the same time being able to hear the other sideof the conversation through the receive or ear speaker 712. The mobilephone application 724 also responds to the user's selection of thereceiver volume, by detecting actuation of the physical volume button710. Although not shown, the processor 704 may include a cellular baseband processor that is responsible for much of the digital audio signalprocessing functions associated with a cellular phone call, includingencoding and decoding the voice signals of the participants to theconversation.

The device 700 may be placed in either the digital camera mode or themobile telephone mode, in response to, for example, the user actuating aphysical or virtual (soft) menu button 708 (e.g., 108 in FIGS. 1 and 5)and then selecting an appropriate icon on the display device of thetouch sensitive screen 704. In the telephone mode, the mobile phoneapplication 724 controls loudness of the receiver 712, based on adetected actuation or position of the physical volume button 710. In thecamera mode, the camera application 728 can respond to actuation of abutton (e.g., the volume button 710) as if the latter were a physicalshutter button (for taking pictures). This use of the volume button 710as a physical shutter button may be an alternative to a soft or virtualshutter button whose icon is simultaneously displayed on the displaydevice of the screen 704 during camera mode and is displayed near thepreview portion of the display device of the touch sensitive screen 704.

An embodiment of the invention may be a machine-readable medium havingstored thereon instructions which program a processor to perform some ofthe operations described above. In other embodiments, some of theseoperations might be performed by specific hardware components thatcontain hardwired logic. Those operations might alternatively beperformed by any combination of programmed computer components andcustom hardware components.

A machine-readable medium may include any mechanism for storing ortransmitting information in a form readable by a machine (e.g., acomputer), not limited to Compact Disc Read-Only Memory (CD-ROMs),Read-Only Memory (ROMs), Random Access Memory (RAM), and ErasableProgrammable Read-Only Memory (EPROM).

FIG. 8 shows an example of a data processing system according to anembodiment of the present invention. This data processing system 3200may include a processor, such as microprocessor 3202, and a memory 3204,which are coupled to each other through a bus 3206. The data processingsystem 3200 may optionally include a cache 3208 which is coupled to themicroprocessor 3202. The data processing system may optionally include astorage data processing system 3240 which may be, for example, any typeof solid-state or magnetic memory data processing system. Storage dataprocessing system 3240 may be or include a machine-readable medium.

This data processing system may also optionally include a displaycontroller and display data processing system 3210 which is coupled tothe other components through the bus 3206. One or more input/outputcontrollers 3212 are also coupled to the bus 3206 to provide aninterface for input/output data processing systems 3214 and to providean interface for one or more sensors 3216 which are for sensing useractivity. The bus 3206 may include one or more buses connected to eachother through various bridges, controllers, and/or adapters as is wellknown in the art. The input/output data processing systems 3214 mayinclude a keypad or keyboard or a cursor control data processing systemsuch as a touch input panel. Furthermore, the input/output dataprocessing systems 3214 may include a network interface which is eitherfor a wired network or a wireless network (e.g. an RF transceiver). Thesensors 3216 may be any one of the sensors described herein including,for example, a proximity sensor or an ambient light sensor. Image sensor3259 captures an image via light focused by lens 3263.

In certain embodiments of the present disclosure, the data processingsystem 3200, device 700, or combination of system 3200 and device 700can be used to implement at least some of the methods discussed in thepresent disclosure.

The invention is not limited to the specific embodiments describedabove. There are numerous other variations to different aspects of theinvention described above, which in the interest of conciseness have notbeen provided in detail. Accordingly, other embodiments are within thescope of the claims.

1. A machine-implemented method for operating a portable, handheldelectronic device having a built-in digital camera and a display screen,comprising: displaying on the display screen an image that is capturedby the camera; receiving, on the display screen, a user selection of aselected region displayed on the display screen; in response to the userselection, initiating a touch to focus mode in which the cameraautomatically focuses using a focus area associated with the selectedregion; automatically monitoring data representing a set of light valuesof the focus area for images captured by the device; and comparing datarepresenting a first set of light values of the focus area of a firstcaptured image to data representing a second set of light values of thefocus area of a second captured image to determine whether a sceneassociated with the focus area has changed, wherein determining whetherthe scene has changed comprises determining whether the datarepresenting the first set of light values and the data representing thesecond set of light values are approximately equal to each other orwithin a predetermined value of each other, wherein the touch to focusmode adjusts exposure parameters for an exposure metering areaassociated with the selected region if the data representing the firstset of light values and the data representing the second set of lightvalues are approximately equal to each other or within a predeterminedvalue of each other.
 2. The method of claim 1 wherein the display screenis a touch sensitive screen and the user selection further comprises oneof a tap, a tap and hold, a single-point gesture, and a multi-pointgesture.
 3. The method of claim 1 further comprising: automaticallydetermining a location of an exposure metering area based on a locationof the selected region with respect to the touch sensitive screen; andautomatically applying an automatic exposure mechanism to the exposuremetering area associated with the selected region.
 4. The method ofclaim 3 further comprising: displaying on the touch sensitive screen acontour surrounding the selected region with the contour representingthe metering area.
 5. The method of claim 1 further comprising:automatically determining a location of the focus area based on alocation of the selected region, wherein the location of the meteringarea is based on the location of the focus area.
 6. The method of claim1 further comprising: terminating the touch to focus mode if the scenechanges; and initiating a default automatic focus mode.
 7. The method ofclaim 6 wherein the default automatic focus mode further comprises:setting the exposure metering area to substantially full screen; andmoving the focus area from the selected region to a center of thescreen.
 8. A machine readable non-transitory medium containingexecutable computer program instructions which when executed by a dataprocessing system cause said system to perform a method, the methodcomprising: displaying on the display screen an image that is capturedby the camera; receiving, on the display screen, a user selection of aselected region displayed on the display screen; in response to the userselection, initiating a touch to focus mode in which the cameraautomatically focuses using a focus area associated with the selectedregion; automatically monitoring data representing a set of light valuesof the focus area for images captured by the device; and comparing datarepresenting a first set of light values of the focus area of a firstcaptured image to data representing a second set of light values of thefocus area of a second captured image to determine whether a sceneassociated with the focus area has changed, wherein determining whetherthe scene has changed comprises determining whether the datarepresenting the first set of light values and the data representing thesecond set of light values are approximately equal to each other orwithin a predetermined value of each other, wherein the touch to focusmode adjusts exposure parameters for an exposure metering areaassociated with the selected region if the data representing the firstset of light values and the data representing the second set of lightvalues are approximately equal to each other or within a predeterminedvalue of each other.
 9. The medium of claim 1 wherein the display screenis a touch sensitive screen and the user selection comprises a tapselection or a tap and hold selection.
 10. The medium of claim 9 themethod further comprising: automatically determining a location of theexposure metering area based on a location of the selected region withrespect to the touch sensitive screen; and automatically applying anautomatic exposure mechanism to the exposure metering area associatedwith the selected region.
 11. The medium of claim 8 the method furthercomprising: automatically determining a location of the focus area basedon a location of the selected region, wherein the location of themetering area is based on the location of the focus area.
 12. The mediumof claim 8 the method further comprising: terminating the touch to focusmode if the scene changes; and initiating a default automatic focusmode.
 13. The medium of claim 12 wherein the default automatic focusmode further comprises: setting the exposure metering area tosubstantially full screen; and moving the focus area from the selectedregion to a center of the screen.
 14. An image capturing device having abuilt-in digital camera and a touch sensitive screen, comprising: adigital camera having a lens; a touch sensitive screen, coupled to thecamera, the screen to display an image; and a processing system, coupledto the screen, the processing system is configured to receive a userselection of a region displayed on the touch sensitive screen, toinitiate a touch to focus mode based on the user selection, the touch tofocus mode to automatically focus using a focus area associated with theselected region; and the processing system is configured toautomatically monitor data representing a set of light values of thefocus area for images captured by the device and to compare datarepresenting a set of light values of the focus area of a first capturedimage to data representing a set of light values of the focus area of asecond captured image to determine whether a portion of a sceneassociated with the focus area has changed, wherein to determine whetherthe scene has changed comprises determining whether the datarepresenting the first set of light values and the data representing thesecond sets of light values are approximately equal to each other orwithin a predetermined value of each other, wherein the touch to focusmode adjusts exposure parameters for an exposure metering areaassociated with the selected region if the data representing the firstset of light values and the data representing the second set of lightvalues are approximately equal to each other or within a predeterminedvalue of each other.
 15. The device of claim 14 wherein the userselection further comprises at least one of a tap, a tap and hold, asingle-point gesture, and a multi-point gesture.
 16. The device of claim14 wherein the processing system is further configured to automaticallydetermine a location of the focus area based on a location of theselected region.
 17. The device of claim 14 wherein the processingsystem is further configured to terminate the touch to focus mode if thescene changes and to initiate a default automatic focus mode.
 18. Thedevice of claim 12 wherein the default automatic focus mode furthercomprises: setting the exposure metering area to substantially fullscreen; and moving the focus area from the selected region to a centerof the screen.
 19. A machine-implemented method for operating an imagecapturing device having a display screen, comprising: displaying on thedisplay screen at least one image captured by the image capturingdevice; receiving, on the display screen, a user selection of a selectedregion displayed on the display screen; automatically monitoring datarepresenting a set of light values of the selected region for imagescaptured by the device; automatically comparing data representing afirst set of light values of the selected region for a first image anddata representing a second set of light values of the selected regionfor a second image; and automatically determining whether a scene haschanged by comparing the data representing first and second sets oflight values of the selected region for the respective first and secondimages, wherein automatically determining whether the scene has changedcomprises determining whether the data representing the first set lightvalues and the data representing the second set of light values areapproximately equal to each other or within a predetermined value ofeach other, wherein a touch to focus mode adjusts exposure parametersfor an exposure metering area associated with the selected region if thedata representing the first set of light values and the datarepresenting the second set of light values are approximately equal toeach other or within a predetermined value of each other.
 20. The methodof claim 19 wherein automatically comparing the data representing thefirst set of light values of the selected region for the first image andthe data representing the second set of light values of the selectedregion for the second image comprises comparing a histogram of a firstluminance distribution of the first set of light values with a histogramof a second luminance distribution of the second set of light values.21. The method of claim 19 wherein the display screen is a touchsensitive screen and the user selection further comprises one of a tap,a tap and hold, a single-point gesture, and a multi-point gesture. 22.The method of claim 19 further comprising: initially setting theexposure metering area to surround the selected region by apredetermined amount in response to the user selection; and setting theexposure metering area to substantially full screen if the scene haschanged.
 23. The method of claim 19 further comprising: initiallysetting a focus area location based on a location of the selected regionin response to the user selection; and moving the focus area from theinitial focus area location to a center of the screen.